1. Field of the Invention
The present invention relates to a method of manufacturing a printed article having a pseudo three-dimensional image display including tactile surface texture. Examples of such articles are trading cards, greeting cards, signs, posters, labels, decals, book covers, decorative panels, and name plates.
2. Description of the Related Art
Three-dimensional images are highly desirable due to the added visual impact provided by depth. Various methodologies have been proposed in the prior art to provide three-dimensional images using two-dimensional media.
One proposal involves printing two offset images in different colors on an opaque or transparent sheet, and viewing the images using special glasses having right and left lenses which correspond to the different image colors respectively. Where the sheet is transparent, the offset images can be projected onto a screen to produce a three-dimensional slide show or movie. Holographic technology can also be used to produce an image on a flat sheet which appears three-dimensional when illuminated and viewed at the proper angles.
However, these methodologies have not been commercially popular for various reasons. The offset image method is undesirable in that special glasses are required to view the image. Holograms are difficult and expensive to produce.
For this reason, processes have been proposed to produce pseudo three-dimensional images which are basically two-dimensional, but have some quality that simulates depth. One such process is conventional embossing, which forms a raised pattern on a business card or the like by physically deforming part of the card upwardly.
Conventional embossing, although practical in some applications, suffers from the drawback that an expensive press is necessary to perform the operation, and a die bearing the desired embossed pattern must be made for each application. The cost becomes prohibitive for large image displays such as signs, and the process is not usable at all for sheets made of materials such as glass which are not readily deformable at temperatures below their considerably high melting points.
U.S. Pat. No. 4,933,218 to L. Longobardi discloses a method for producing a sign having an embossed appearance which does not require physical deformation. The method involves printing an extraordinarily thick ink pattern on the rear surface of a transparent sheet, and printing a transparent ink image in areas not occupied by the thick ink pattern. A reflective layer is then formed over the ink pattern and image.
The sign is viewed through the transparent sheet such that light is reflected back from the reflective layer through the ink pattern and image. The ink image has a normal two-dimensional appearance when thusly viewed. The thick ink pattern is formed around edge and other desired portions of the image to produce a pseudo three-dimensional effect which simulates embossing. An alternative is to produce an etched effect using a textured ink pattern rather than a thick ink pattern.
A variation of this method is disclosed in U.S. Pat. No. 5,082,703, also to Longobardi, in which the reflective sheet is replaced by a reflective stratum which can be sprayed onto the rear surface of the sheet.
U.S. Pat. No. 5,106,126, to L. Longobardi and D. Lovison, discloses a colored image consisting of a large number of small dots, in combination with a stratum of opaque white ink deposited between a reflective layer and preselected portions of the image to block passage of visible light from the preselected portions to the reflective layer. U.S. Pat. No. 5,223,357, to D. Lovison, discloses an arrangement similar to that of U.S. Pat. No. 5,106,126 in which the reflective layer is replaced by a holographic layer to present a variable color cast to the image.
A problem which exists with the Longobardi and Lovison proposals are that they require a transparent sheet of glass, plastic, etc., with the image being formed on a rear surface of the sheet which faces away from the viewer. These methods are not readily applicable to producing printed articles such as trading cards which have opaque, in this case cardboard, base sheets. More specifically, a second sheet on which the rear surface image is formed must be laminated to the rear surface of the transparent sheet.
In addition, the ink pattern and ink image are located underneath the front surface of the sheet and cannot be felt by a person handing the article. For this reason, the prior art arrangements cannot produce an article which has a desirable tactile surface texture that can be felt by touch.
Known lamination methods present certain problems. Not only does lamination add to the cost of producing two-sided objects, but misregistration (misalignment of the images on opposite sides of the sign, poster or card relative to one another) is often introduced during the lamination process. Through the structure and method of the present invention, this registration problem is greatly reduced if not eliminated.
A need therefore exists in the art for a method of producing a printed article having a pseudo three-dimensional image which can be advantageously applied to manufacturing two-sided trading cards and the like which have opaque base sheets.